pup vs youth

pup and youth both are nouns.

Word	Noun	Adjective	Verb	Adverb
pup	Yes	No	Yes	No
youth	Yes	No	No	No

As nouns, youth is a hypernym of pup; that is, youth is a word with a broader meaning than pup:

Other hypernyms of pup include spring chicken, young person, younker.

pup (noun)	youth (noun)
young of any of various canines such as a dog or wolf	the freshness and vitality characteristic of a young person
an inexperienced young person	young people collectively
	a young person (especially a young man or boy)
	early maturity; the state of being young or immature or inexperienced
	the time of life between childhood and maturity
	an early period of development

pup (verb)	youth (verb)
give birth to (a puppy)